Cat Laws

[Snoranger]

Can you tell me where this is stated by the feds? I've searched and can't see it anywhere. All I can see is that automakers were required to put them on 72 and newer.

I wonder why, if this is a federal law, a county has it's own set of laws that it goes by?

I'm not trying to disprove anyone, I just can't find it anywhere. I'd also like to have it bookmarked because this topic comes up a lot on this and other forums I frequent.

EDIT: I've found these docs on the EPA site, but I don't see it saying it has to be on any 75 and newer car.

http://www.epa.gov/oms/consumer/warr95fs.txt

http://www.epa.gov/oms/cert/factshts/catcvrts.pdf

Right here.

http://www.epa.gov/compliance/resources/policies/civil/caa/mobile/exhsysrepair.pdf

 

[tanbuddy]

I live in a shitty emission county in pa, my truck passed with just the first cat and its holllowed out. What a bullshit law my next truck is gonna be diesel so i dont have to deal with it.

 

[Nathan123]

Thanks tanbuddy thats what I thought, if theres something that looks like a cat down there, your good to go. In reality its a little pointless because if there isn't a tailpipe test, what does it matter if there's a cat or not. "Oh yeah I have a cat but it doesn't do shit." I hate complying with vehicle laws.

 

[cammeddrz]

from that link:

a repair facility should consult with the State to
determine if the State has a similar policy towards this type of
repair work or how State laws may affect the legality of its
actions.

from that i am getting a mixed understanding of which is prevalent. local or federal

 

[gribly]

It's retarded to have a hollowed out cat on your exhaust. A properly functioning modern cat WILL flow better than a hollowed out cat, and there is a scientific reason for this. The hollow cat acts as an expansion chamber, and slows down exhaust gasses, which then speed up when they enter the exhaust pipe again. This creates an area with a lot of friction and resistance, so flow drops. Add in the turbulence added by the air flowing away and then towards itself due to the expansion chamber, you have some shitty flow.

The ONLY time hollowing out a cat increases horsepower is when you hollow out a clogged one, which is a no-brainer what the effects of that are.

 

[cammeddrz]

A properly functioning modern cat WILL flow better than a hollowed out cat

here i'll fix it

A properly functioning modern cat mightflow as well as a hollowed out cat but not likely

 

[heptofite]

It's retarded to have a hollowed out cat on your exhaust. A properly functioning modern cat WILL flow better than a hollowed out cat, and there is a scientific reason for this. The hollow cat acts as an expansion chamber, and slows down exhaust gasses, which then speed up when they enter the exhaust pipe again. This creates an area with a lot of friction and resistance, so flow drops. Add in the turbulence added by the air flowing away and then towards itself due to the expansion chamber, you have some shitty flow.

The ONLY time hollowing out a cat increases horsepower is when you hollow out a clogged one, which is a no-brainer what the effects of that are.

which is why smart folk drive a pipe through the chamber to prevent expansion.

 

[shane96ranger]

i am getting a mixed understanding of which is prevalent. local or federal

It is confusing. From what I see around here, I believe the local law to take precedence. I've heard the guy at the Muffler shop tell a customer he couldn't remove the cat at his shop, but it was OK for it not to be there on an older Corvette (about a 1979).

The document also says it is illegal to sell off road pipes or install an off road pipe:

Section 203(a)(3)(8) makes it illegal for any
person to sell or to install any part where a principal effect would
be to bypass, defeat, or render inoperative any device or element of
design of a vehicle's emission control system.

If this is true, they should flip through a Jegs or Summit catalog.


EDIT - This is all the way at the bottom:

Please consult with State officials regarding applicable
State laws. Shops are encouraged to convince the vehicle
owner to restore the exhaust system back to its original
configuration.

I think this says it all

 

[Snoranger]

Here's how it works.

The feds made the law, its up to the state or county to choose to enforce it. If they do, you have to abide by the law. If they dont enforce it, then do whatever you want with your cat.

BUT, trust me, you dont want to get a d!ck cop in an "enforced" area to catch you without cats. A close friend got caught with no cats on his 91 Mustang in high school. MAX $5000 fine per cat x 4 missing cats = $20,000 + court costs. But they let him go on the DWI. He got a payment plan $10 a month for 2000 months .

 

[shane96ranger]

I think the important thing to remember is, this thread is about wanting to be legal. I really don't think someone will fail you for going from the stock 2 cat setup to a single 3-way cat setup. My Mustang has gone from the 4 cat H-Pipe to a 2 cat H-Pipe with less emission output, and I've never had anyone say boo to me about it.

I, like some of the other people who have posted here, are curious about the federal law claims.

To the OP, I have experience with 2 brands of aftermarket cats. The Magnaflow's and Catco. The Magnaflow's are high flow and sound very nice. This is my experience with Catco's below. This cat busted and flipped around inside with very little use on it.

 

[gribly]

here i'll fix it

Try and back that with evidence, please, to enlighten and educate the rest of us.

 

[Nathan123]

Thanks shane96ranger I think I'll go with a universal magnaflow and run it into a muffler (magnaflow or thrush, maybe stock if i dont have money) and then make a single side pipe, probably with a resonator. I want a nice sound, but it has to be a DD so I cant be pissin off any cops.

 

[94xlt4.0]

if your in a emissions testing area it would be best to go talk to someone where your going to get the test done. if you only have visual then i wouldnt worry about the difference. most of the guys who do the inspections will look at the exhaust and see a cat and be fine done with it. the more inspections they can knock out the more money they make so its about speed for them

 

[Sasquatch_Ryda]

I live in a shitty emission county in pa, my truck passed with just the first cat and its holllowed out. What a bullshit law my next truck is gonna be diesel so i dont have to deal with it.

You don't think that diesels have converters on them? 2003 and newer fords do. Not sure about everyone else.